A new version of FurMark was released yesterday, this is an utility for benchmarking and stressing GPUs:
FurMark is an OpenGL benchmark that stresses the GPU with fur rendering. The benchmark offers several options allowing the user
to tweak the rendering: fullscreen / windowed mode, MSAA selection, window size, duration. The benchmark also includes
a GPU Burner mode (stability test). This new version fixes some minor bugs and adds command line parameters as well as
a Xtreme Burning mode (see the start-Xtreme-Burning.bat file) to overheat the GPU!